Cr own d buccal groove to middle third, pit e crest of contour cervical third
Crown d.buccal groove to middle third,pit e.crest of contour cervical third
C r own 2)Lingual sur face a. resemb e but ess than b 2 cusps(fifth cusp) c di l inguaI groove d. crest of contuor middle 1/3
Crown 2）lingual surface a.resemble but less than b.2 cusps(fifth cusp) c.distolingual groove d.crest of contuor middle 1/3
Cr own 3) proximal sur face a. quadrangle bucco l ungual ly wider, buccal margin straight b buccal cusp higher (2/5) I ingual cusp rounder (3/5) d long axis
Crown 3）proximal surface a. quadrangle,buccolingually wider,buccal margin straight b.buccal cusp higher（2/5） lingual cusp rounder（3/5） d.long axis
Cr own 4) occlusal sur face a. rhombus bucca margin sloping d-L 4 angles acute ang le obtuse angle b. 4 marginaI ridges
Crown 4）occlusal surface a. rhombus,buccal margin sloping D-L 4 angles acute angle obtuse angle b.4 marginal ridges
Cr own bucca sur face C 4 cusps: inc ined sur face buccal cusps higher and sharper size: M-L>M-B>D-B>D-L hei ght: M-B>M-L. D-B>D-L triangular ridges: ob l ique ridge (D-B TO M-L)
Crown buccal surface c.4 cusps： inclined surface buccal cusps higher and sharper size：M-L>M-B>D-B>D-L height：M-B>M-L、D-B>D-L triangular ridges:oblique ridge （D-B TO M-L）